Glass painting method

ABSTRACT

A procedure is disclosed for the production of paintings on glass, the subjects of the paintings being, for example, original paintings, engravings, lithographs and like articles whose appeal is primarily aesthetic. A low-contrast image of the subject is first produced using a photographic film, preferably a fine-grain medium contrast panchromatic film, the image is projected on to a photographic glass plate which is preferably coated with a slow, blue-sensitive high contrast orthochromatic emulsion having very fine grain and very high resolution, a clear varnish is applied to the emulsion side of the glass plate and the image is colored by application of paint to the varnish coating.

This invention relates to a method for the production of glass paintingsand, more particularly, to a method of producing on glass, in the formof painted reproductions, original paintings, engravings, lithographsand like articles whose appeal is primarily aesthetic.

Although mass markets for paintings, engravings and the like can besatisfied to some extent by the production of prints, prints generallytend to lack many of the aesthetically attractive features of originals,in particular, depth of colour characteristic of paintings or finenessof detail.

According to the present invention, there is provided a process for theproduction of a painted reproduction on glass, hereinafter termed aglass painting, of a painting, engraving, lithograph of like article,hereinafter termed "the subject", which comprises colouring an image ofthe subject on a glass plate, the image having been produced on theglass plate by photographing the subject using a photographic film,processing the film to produce a low-contrast image and projecting theimage on to a photographic glass plate, the emulsion side of the glassplate being coated with a clear varnish prior to colouring the image byapplication of paint to the varnish coating.

In carrying out the process of this invention, the subject to be copiedis photographed. It has been found most suitable to employ a largeformat (5 inches × 4 inches) fine grain medium contrast panchromaticfilm. The film is then processed in a fine grain developer selected togive a fairly low contrast image, usually an image having a gamma valueof from 0.3 to 0.6, more especially a gamma value of approximately 0.4

If it is desired to alter or retouch the original image in any way, thisshould be done at this stage. For this purpose, a black and white printis made of the image and the necessary retouching or alterations arecarried out on the print. The print is then rephotographed in theaforesaid manner.

In the next stage in the preparation of an outline for painting in ofcolours, the image on the negative is projected onto a photographicglass plate. The image will usually be enlarged to the size of theintended product. The glass plate onto which the image is projected andusually simultaneously enlarged is preferably coated with a slow,blue-sensitive high contrast orthochromatic emulsion having a very finegrain and very high resolution if an image having characteristicsrendering it particularly suitable for further processing is to beobtained. The use of such an emulsion ensures that only the lines in theimage are reproduced, the tones disappearing so that only clear glass isleft between the lines. The glass is then processed, washed and dried inthe normal way for photographic glass plates. Although a variety offormulations can be employed for slow buel-sensitive emulsions, IlfordN-50 plates and Agfa-Gevaert HD plates have been found to beparticularly suitable.

Although an image which reproduces in outline features of the desiredpainting will have been produced, it is generally not practicable topaint in the desired colours on the photographic plate thus produced.The black lines present on the plate at this time will tend to dominatethe applied paint too sharply. It is generally desirable to employ asofter lined image at the painting stage. For this purpose, the glassplate is toned by first undergoing immersion in a chemical bath whichbleaches out the image, washing the plate and placing it in a toningbath wherein a new image toned the desired colour is obtained. Forpractical and aesthetic reasons, the image is preferably toned sepia.

Since paint cannot be readily applied to glass, the emulsion side of theglass plate is then coated with a clear varnish and allowed to dry. Thevarnish used may be any conventionally applied polyurethane-basedvarnish, preferably a matt varnish or a gloss varnish diluted withturpentine or turpentine substitutes (white spirit) to reduce its gloss.The varnish enables paint to be applied evenly to the glass plate and,if suitably tinted, for example golden-brown, can impart a warmcolouration to the painted product subsequently obtained.

Finally, the image is painted by an artist working directly on thevarnished side of the glass. The artist is, in fact, "colouring in" theimage already on the glass plate. The fine colour detail is preferablyfirst applied with care to improve the depth and quality of the finishedpainting. When the detailing is dry, normally 24 hours later, thepainting in is completed. The colouring is simply blended in on theemulsion side of the plate in accordance with the image thereon. Thereis no need for skilled attention to detail as all the detail in thefinished painting is supplied by the image already providedphotographically on the plate. When the additional paint has dried, theglass painting obtained may be utilized for any desired purpose, forexample for framing and hanging on the wall, or for a coffee table top.

For a better understanding of the invention and to show how the same canbe carried into effect, reference will now be made, by way of exampleonly, to the accompanying drawings which show the stepwise production ofa painting on glass by a preferred process embodying this invention. Ineach of the drawings like reference numerals represent like features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a glass plate sensitized on one face.

FIG. 2 is a view of an image projected onto a glass plate.

FIG. 3 is a view of a bleached image projected onto a glass plate.

FIG. 4 is a view of a bleached image toned sepia projected onto a glassplate.

FIG. 5 is a view of a glass plate coated with a varnish.

FIG. 6 is a view of a glass plate partially coated with a layer ofpaint.

FIG. 7 is a view of a glass plate completely coated with a layer ofpaint.

FIG. 8 is a reverse view of FIG. 7.

FIG. 1 shows a starting glass plate 1 sensitised on one face thereofwhich, in the sense of the drawing, is the front face of the plate. Thesensitising emulsion employed is a slow blue-sensitive emulsioncontaining gelatin as colloid, silver nitrate and silver bromide asoptical sensitisers, plasticisers and stabilisers. Typical plates ofthis type are Ilford N-50 plates and Agfa-Gevaert HD plates. FIG. 2shows an image 2 on a negative which has been projected onto thephotographic glass plate 1. This image will have been produced byphotographing a subject, in this case shown to be a simple cube having adetail 3 for convenience in representation in the drawings, but inpractice generally a subject having much greater detail. The subject isphotographed using a photographic film which is processed to produce alow-contrast image which is projected onto the photographic glass plate.A large format fine grain medium contrast panchromatic film ispreferably employed and the fine grain developer employed preferably hasa gamma value of from 0.3 to 0.6.

The image produced on the glass plate 1 in FIG. 2 is quite bold and if asubject containing considerable detail is employed, a substantiallyblack mass of detail will show on the plate. At this stage, the emulsionon the plate 1 contains metallic silver suspended in gelatin containingsilica and traces of saponine. All other components of the originalemulsion on the plate 1 will have been removed by processing. Hence forpractical purposes, it is necessary to reduce the intensity of the image2 on the plate 1 and accordingly the image is bleached out as shown inFIG. 3, all the metallic silver in the emulsion on the plate beingremoved. The bleached image is given the reference numeral 2'. The imageis now too faint to be of practical value and is toned to the desiredintensity. Sepia toning is preferred. FIG. 4 shows the bleached image 2'of FIG. 3 now toned sepia and given the reference numeral 2".

Referring next to FIG. 5, the emulsion side of the glass plate 1 isprovided with a coating 4 of matt polyurethane varnish to which stainerhas been added to produce a golden-brown tone. The varnish has the dualeffect of protecting the image from being damaged and making it possiblefor an artist to paint directly onto the varnished image. Thegolden-brown stainer is employed in preferred practice so that the paintlater applied to the glass should be seen through the golden-brown tonewhich slightly mutes the colour of the paint and gives it a more"antique" appearange.

Referring next to FIG. 6, the detail 3 of the image is painted in byapplication to the image on the varnish side of the plate, with care, ofa layer of paint 5.

The final stage in the production of a glass painting is shown in FIG. 7which shows the finished product obtained by applying paint withsomewhat less care to the remaining areas of the image on the glassplate on the varnish side thereof than used in the filling in of thedetail 3. The plate is turned over in FIG. 7 whereon it can be seen thatthe detail of the various features of the image showing through theplate masks any slight imperfection in the application of paint to thevarnished side of the plate. Thus additional areas 7, 8, 9 and 10 of theplate hve paint applied thereto. It is appreciated that it is difficultto fully indicate the different visual effects of the two sides of thefinished plate since the differences are largely aesthetic. However,reference is finally made to FIG. 8 of the drawings which shows a detailof FIG. 7 in reverse, that is the emulsion/varnish side of the plate, onan enlarged scale. Instead of there being a straight line boundarybetween the painted areas 7 and 10, there is in fact a narrow zone 11free from paint. Between the painted area 10 and the detailed area 5 itis a narrow zone 12 which is also free from paint. However, the zone 12has a straight margin adjacent the area 5 indicating the care with whichthe detail of the area 5 has been painted in, in contrast to therelatively ragged margin against the area 10.

I claim:
 1. A process for the production of a painted reproduction onglass of a subject, which comprises photographing the subject using afine grain medium contrast panchromatic photographic film, processingthe film to produce a low-contrast image, projecting the image on thefilm as a black image on to a photographic glass plate coated with aslow, blue-sensitive high contrast orthochromatic emulsion having veryfine grain and very high resolution, bleaching out the black imageproduced on said glass plate and toning said image in a colour otherthan black, coating the emulsion side of the glass plate with a clearvarnish, and colouring the image on the glass plate with paint appliedto the varnish coating in two stages, paint first being applied todetailed parts of the image in substantially exact conformity with themargins of the detail and paint thereafter being applied to remainingparts of the image after drying the paint applied to the detail parts,the paint being applied to said remaining image parts in such mannerthat small zones free of paint exist between adjacent painted areas. 2.A process as claimed in claim 1, wherein the film is processed in a finegrain developer selected to give an image having a gamma value of from0.3 to 0.6, preferably about 0.4.
 3. A process as claimed in claim 1,wherein a black and white print is made of the low-contrast image, theimage is retouched or altered on the print and the print is photographedusing a photographic film and processed to produce the low-contrastimage which is projected on to the photographic glass plate.
 4. Aprocess as claimed in claim 1, wherein the image is enlarged as it isprojected on to the photographic glass plate.
 5. A process as claimed inclaim 1, wherein the image on the glass plate is toned sepia.
 6. Aprocess as claimed in claim 1, wherein the varnish applied to theemulsion side of the photographic glass plate is a matt polyurethanevarnish.